Process for treating worn or waste rubber or the like for the utilization therefof.



this waste rubber or according to a an srarns PATENT, ornron.

WALTER EDWIN WINDSOR RICHARDS, OF LONDON, ENGLAND, ASSIGNOR TO THEBOURNE RUBBER COHPANY, LIMITED,'OF LONDON, ENGLAND.

PROCESS FOR TREATING WORN OR WASTE RUBBER OR TION THEREOF.

I ,O53A39. No Drawing.

Patented Feb. 18,1913; Serial No. 663,773. i

To all whom it may concern:

Be it known that I, WALTER EDWIN WIND- sor Rrormnns, mining engineer, asubject of the King of Great Britain, residing at 50 Great Tower street,London, England, have invented a certain New or Improved Process forTreating Worn or Waste Rubber or the Like for the Utilization Thereof,.of which the following is a specification.

This invention has for its object the utilization of old, worn, orwasterubber or the like such as. old rubber tires or tire covers for motor orother wheels; and is especially applicable for treating old, worn, orwaste vulcanized rubber. 1

In the treatment, according to this invention of such old, worn, orwaste rubber or the like, (hereinafter referred to as waste rubber I mayform a permanent mixture of other substance or substances with suchwaste rubber and I may inold and vulcanize or the aforesaid orcomposition (of waste rubber and other substances) into any suitablearticle or shape which after being vulcanized will become very hard whencold and set or after first treating this waste rubber in accordancewith this invention I may then either alone or mixed with firstvulcanize same and re-heat same until the mass assumes a granular orsubdivided form and thereafter mold (either hot or cold) and press thematerial thus formed; further modification I may, after treating thewaste rubber according to this invention remove the mass to mixing rollsor the like and then incormold and 'vulcanize in usual manner or v'ulcanize before molding.

In carrying out the present invention, I take the waste rubber (such forexample as old motor tires or old vulcanized rubber goods) irrespectiveof whether it contains or has mixed therewith any foreign sub stance orsubstances such as canvas (in the case of old motor tires) or-dirt; andI subdivide or disintegrate same as required for example I may cut ortear same up into pieces, or I may grind or otherwise reduce same to apowder or finely divided condition; and I subject the mass to a suitablehigh temperature in any suitable manner mixture other substance orsubstances) namely to such'a temperature and for such a time that thewaste rubber will be fused or melted and suchhightemperatur I have foundto be about 300.C. but I do not confine myself thereto; and this heatingmay advantageously be efl'ected while agitating stirring or. mixing thematerial in a mixing machine (of any suitable type) until the whole,mass is more or less homogeneous.

I may introduce and mix with the waste rubber either (a) before, or (6)during or (0) aftenheating up the said. waste rubber to its fusing ormelting polnt as aforesaid any suitable substance or substances to serveas filling or strengthening material or other- .wise; for example incases where it is desired to form a hard substance .I may use a mixtureof waste rubber and asbestos, as

follows :Either before during or after fusing or melting the wasterubber under considerable heat as aforesairLI mix asbestos (in a finelydivided state-therewith) "and THE LIKE FOR rim UTILIZA- after the masshas been brought to a homogeneous state, this-plastic mass(advantageously after being allowed to cool down somewhat) has sulfurmixed therewith and thereafter (a) this mixture is removed from themim'ng machine andmolded or otherwise formed into the desired shape orform and vulcanized; or (6) this mixture (plastic mass) is removed tosuitable rubber'mixing machinery such as the well-known rubber mixingrolls where new rubber is mixed and incorporated therewith after whichthis mixture is molded and vulcanized or (0) before removal from themixing machine the temperature of the mass may be raised say to avulcanizing temperature or to such a temperature while the mass is stillin the mixing machine that same will finally assume a hard granular formafter which it is taken out of the mixing machine and molded in hotmolds to the shape' or form required. This last-named method has theadvantage that the articles can be pressed or molded and released fromthe-mold immediately and moreover leave the mold with a high polish: andfurthermore necessity of any separate vulcanizing machinery." When thewaste rubber is fused or melted underzconsiderable heat as aforesaid(either with or without previous admixture with asbestos or any othersuit- .a plastic sticky mass. lowed to drop a little to terial is takenfrom the machine,

may be employed by able heat resisting solid it will be found that it(particularly waste vulcanized rubber) has,'or has acquired, theproperty of solubility in benzol or other rubber solvent.

The following are examples of the manner of working the processaccording to the present inventio :-The rubber waste is well stirred ina-suitable mixingand heating machine such for exam le as the well-knownWerner-Pfieiderer 'mac lline (either with or without any added substanceor substances such for example as asbestos) the heat being raised andmaintained until the. rubber has fused or melted, and the whole hasbecome The heat is then .al-

such a temperature that sulfur can" be added and'the sulfur is thenadded and well mixed into the rub-.

ber (and asbestosifused). The quantity ofsulfur depends on the class of:article to be produced for example I may add from say 4% or 5% (byweight) u tosay 25% of sulfur the mass. After; adding the sulfur'theheat 1s applied again and the temperature of the mass raised again and achange begins to then take place in the mass in the mixer viz. the massheginsto lose its sticky nature and becomes drier,

canized; and in ized rubber waste same apparently becomes revulcanized)other changes are also taking place; the compact ma'ss being broken upinto minute particles '15. e. the mass finally assumes a :hard granularform which is most convenient for the working or molding of the goodsafterward; I granular maand either in a hot or cold state can be pressedin-molds, wh ch may be hot molds, and the finished article taken out;.After the sulfur has been added tot-he fused waste rubbera variationnow taking the plastic mass out of the machine and rolling it intoplates or molding it into any convenient forms or shape after which itis transferred to an ordinary vulcanizer andthere vulcan- I ized underknown conditions. Articles made in this way have remarkable properties.Arholes which have'a certain ency maybe made by to the amount of rub erpresent in (apparently becoming vulthe case of already .vulcan wasterubber which amount of resiliadding only a small quantity of sulfurto'the fused mass and vulcanizing for a shorttime.

According to another modification; after fusing or melting the wasterubber, the lastic mass thus formed may have new ru ber mixed therewithin any suitable manner as for example the said lastic mass-either withor without the addition of any filling substance such as asbestos-may beremoved from the heatin machine to mixing apparatus of any suita le typesuch as mixing rolls of the well-known type and there mixed andincorporated with new rubber (a v suitable roportion of sulfur beingmixed therewith) after which this mixture is then molded and vulcanizedor finished in ner.

What I claim is 1. The herein-described method of treating waste rubbersame under agitation to'a temperature such any suitable man'- thatthe-rubber will be fused or melted next reducing the temperature andthen adding sulfur; mixing a filling or strengthening which consists inheating substance e. g. asbestos with the mass, next raising-thetemperature of the mass until same ally assumes a hard granular form;and then molding same into the desired shapes or articles substantiallyas and for the purposes described.

2. The herein described method of treating consists in heating sameunder agitation. to a temperature of about 300 C. so that the rubberwill be fused or melted, next reducing the temperature of the mass'andthen adding sulfur, mixing a filling or strengthening substance 6. g:asbestos with the mass, perature of the mass until same finally assumesa hard granular form; and then moldin same into the desired shapes orarticles ,su stantially as and for the purposes described.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

WALTER EDWIN Witnesses:

G. GANunB, H. D. JAMEBON.

WINDSORRIGHABDS- next raising the 'tem-

